Molding apparatuses, such as injection molding machines and die-cast machines, comprise a mold clamping apparatus in which a mold, consisting of a fixed mold and a movable mold, is to be mounted, and an injection apparatus. The mold clamping apparatus includes a fixed platen to which the fixed mold is to be mounted, and a movable platen to which the movable mold is to be mounted. There are various types of known mold clamping apparatuses. A typical one is a toggle-type mold clamping apparatus which moves a movable platen back and forth along tie bars through extension/contraction of a power-driven toggle link mechanism, thereby closing, clamping and opening a mold.
In such a mold clamping apparatus, the movable platen is supported on a frame of the molding apparatus via a platen support apparatus so that the movable platen can smoothly move back and forth along tie bars. When a movable mold is mounted on the movable platen, a large load is applied to the tie bars, whereby the tie bars can sometimes slightly bend downward. The amount of downward bend of the tie bars changes with a change in the weight of the mounted movable mold upon mold replacement.
In order to prevent such bend of tie bars, Japanese Patent Laid-Open Publication No. 2003-71894, for example, describes using a linear guide that slides along a guide rail as a platen support apparatus to support the weight of a movable platen. This can eliminate application of a load on the tie bars, thereby making it possible to ensure smooth back-and-forth movement of the movable platen and to prevent bending of the tie bars.
Further, in order to prevent the generation of a bending moment in the movable platen that receives a large force from a toggle link mechanism upon clamping of a mold, it is proposed in the above-cited patent document to fix the linear guide via a mounting block which is elastically mounted to the lower end of the movable platen.